Engine Cooling Questions

[Randy Mitchell]

Does anyone have the technical background to know what optimizes an engine radiator/oil cooler. Specifically: 1-Is there an optimal angle the radiator should be placed into the incoming air? 2-Does the air velocity across the rad fins affect cooling? Will a thicker radiator always provice more cooling? How much more effecient is a double pass radiator verses a single pass (if any)? Does anyone know where to access technical info regarding cooling an engine? I have a Formula B car with fairly small side pods to mount my radiator and engine coolers and I need to optimize this space. Thanks for your help. [email protected]

[Matra et Alpine]

Flow THROUGH a standard radiator is what produces the cooling.
If air is moving fast and for aero reasons you want to do that then you want less fins, easier airflow through the rad.
IF space is the issue then you need to INCREASE the cooling efficiency and for the same size of radiator then you have to increase the surface area of air/fins and that (sadly) then usually leads to more restrictive air flow .... which then AGAIN affects the cooling. Their is a nasty feedback loop in the design stage present.

To "try" to answer ...
1 - yes. Optimal cooling is with air moving perpendicular to the rad, parallel to the fins.
2a - yes. THe more air you can get in contact with the radiator surface then then better the cooling. BUT the heat transfer may not be effective at lower speeds.
2b - yes. The LONGER you can keep cold air in contact with the radiator surface then then better the cooling. But it may stall at lower speeds and reduce cooling.
2c - yes. IF you push the same air through. no, if the thickness reduces the airflow and you get LESS air through
2d - less than double. Too many variables. Radiator SURFACE area is the key design consideration. You can always add fan to prevent stall and keep the volume up and you can always make them deeper if size constraints -- with a stronger/multiple fans.
2e - formula B designers and drivers will show what they run. Find the one getting the fastest times and copy him/her. A good starting point Actually the BEST starting point !

On the tech info, unless you have MAJOR funds, then you start at the radiator manufacturers and look at their air flow (cfm ) and temperature drop (deg C) and water flow rates and see which one(s) then fit in your packaging. Then you have to do LOTS of number crunching to understand the issues present in each. and you wil need to know a LOT about the airflow of the chassis/body you are running as at extremes you can have a significant impact.

You got some links for "Formula B" ? If it's similar to any of the normal formulas I may have some names/suggestions.

[Randy Mitchell]

I have a 2000 Van Diemen converted to a Formula B that requires much more engine and oil cooling. My goal is to use the existing side pods with modified radiator and oil coolers. To optimize engine and oil cooling, how much of an angle to the incoming air will the radiator and oil cooler tolerate before you start losing efficiency? Does a deeper (thicker) radiator always result in more cooling and is there an optimum thickness? Will a double pass radiator/oil cooler always result in more cooling? What can I do aerodynamically to improve cooling within the side pod, ie cut slots in the pods (exhaust side) to help evacuate the air etc. Please, if anyone has a solid background in this arena, please contact me. Randy Mitchell, Salt Lake City, UT. [email protected] 801-541-6252 Thank

[culver]

If I recall there are at least two if not three VD to FB conversions on Apexspeed. I think the members of that forum would know a lot more than hear about such a specific topic.

[Matra et Alpine]

New thread best idea Randy, so I've moved your posts from the tech to here and hope you get good follow up.

[culver]

Mantra,
FB is a recently revived SCCA class. The class was revived with the idea of putting stock 1L bike motors into Formula Continental/F2000 cars. The rules were expanded to include some purpose built cars. I have a link my post in the aero thread to some F1000 info. If done right a converted Van Diemen should be a VERY quick car.